A trinuclear strontium hydride [(Me4TACD)3Sr3(µ2-H)4(thf)][B(C6H3-3,5-Me2)4]2 (Me4TACD = 1,4,7,10-tetramethyl-tetraazacyclododecane) and a mixed calcium strontium hydride [(Me4TACD)2CaSr(µ-H)2(thf)]2+ were isolated by hydrogenolysis of cationic benzyl precursors. A solution of [(Me4TACD)2CaSr(µ-H)2(thf)][B(C6H3-3,5-Me2)4]2 shows hydride ligand...

Oxidative addition of TMEDA-supported [AlH2]+ to [{BDI}Ga] (BDI = {HC(C(CH3)N(2,6-iPr2-C6H3))2) provides [{BDI}Ga(H)-Al(H)(tmeda)]¬[B(C6H3-3,5-Me2)4] (TMEDA = N,N,N’N’-tetramethylethylene¬diamine) with a covalent metal-metal bond. The reaction is readily reversed by substituting TMEDA for an...

The first isolation and structural characterization of a rare-earth metal-terminal imido complex were reported in 2010, but a rare-earth metal-terminal phosphinidene complex is still absent, to date. Herein, we report the synthesis and structure of the first example of a rare-earth-terminal phosphinidene complex, namely the scandium boronylphosphinidene complex. Single-crystal X-ray diffraction shows that the complex has a much shorter Sc−P bond length as compared to that in a related scandium boronylphosphido complex, 2.381(1) Å vs 2.564(1) Å. DFT calculations indicate the presence of a strong Sc−P π interaction in this complex, which is in striking contrast to the weak interaction found in the phosphido complex. A preliminary reactivity study demonstrates that the scandium-terminal boronylphosphinidene complex behaves as a nucleophilic phosphinidene complex.

Salt metathesis reactions between a low-valent rhenium(i) complex and a series of amidinate-supported tetrylenes led to rhenium metallotetrylenes with varying extents of Re–E multiple bonding.

Reaction of the 1,2-disilylene, [{ArC(NDip) 2 } Si] 2 1 (Dip = 2,6-diisopropylphenyl, Ar = 4-C 6 H 4 Bu t ), with CO proceeds via insertion of CO into one SiÀ N bond, and SiÀ Si bond cleavage, to cleanly give the bis(silylene), {ArC(NDip) 2 }Si(:)OCSið:ÞðNDipÞ 2 C Ar 2, under ambient conditions. The reaction can be partially reversed when solutions of 2 are subjected to UV irradiation. The five-membered heterocyclic fragment of 2 represents the first silicon analogue of an "abnormal" N-heterocyclic carbene (aNHC), a view which is substantiated by a computational analysis of the compound. Reaction of 2 with [Mo(CO) 6 ] under UV light affords the chelate complex, [Mo(CO) 4 (k 2 -Si,Si-2)] 3, while reaction with [Fe(CO) 5 ] gives the unusual silyleneyl bridged complex, [{Fe 2 (CO) 6 }{μ-Si[(NDip) 2 CAr]} 2 ] 4. The same coordination complexes can be accessed by reaction of 1 with [Mo(CO) 6 ] or [Fe(CO) 5 ] under UV light. As is the case for aNHCs, d-block metal complexes of bis(silylene) 2 could prove useful as bespoke catalysts for organic transformations.

The cationic benzyl complex [(Me 4 TACD)Sr-(CH 2 Ph)][A] (Me 4 TACD = 1,4,7,10-tetramethyltetraazacyclododecane; A = B(C 6 H 3 -3,5-Me 2 ) 4 ) reacted with two equivalents of phenylsilane to give the bridging hexahydridosilicate complex [(Me 4 TACD) 2 Sr 2 (thf) 4 (μ-k 3 : k 3 -SiH 6 )][A] 2 (3 a). Rapid phenyl exchange between phenylsilane molecules is assumed to generate monosilane SiH 4 that is trapped by two strontium hydride cations [(Me 4 TACD)SrH(thf) x ] + . Complex 3 a decomposed in THF at room temperature to give the terminal silanide complex [(Me 4 TACD)Sr(SiH 3 )-(thf) 2 ][A], with release of H 2 . Upon reaction with a weak Brønsted acid, CO 2 , and 1,3,5,7-cyclooctatetraene SiH 4 was released. The reaction of a 1 : 2 mixture of cationic benzyl and neutral dibenzyl complex with phenylsilane gave the trinuclear silanide complex [(Me 4 TACD) 3 Sr 3 (μ 2 -H) 3 (μ 3 -SiH 3 ) 2 ]-[A], while n OctSiH 3 led to the trinuclear (noctyl)pentahydridosilicate complex [(Me 4 TACD) 3 Sr 3 (μ 2 -H) 3 (μ 3 -SiH 5 n Oct)][A].

The uranyl complexes UO 2 (OAc)( L ) and UO 2 Cl( L ) of the redox-active, acyclic diamido–dipyrrin anion L – are reported and their redox properties explored. Because of the inert nature of the complexes toward hydrolysis and oxidation, synthesis of both the ligands and complexes was conducted under ambient conditions. Voltammetric, electron paramagnetic resonance spectroscopy, and density functional theory studies show that one-electron chemical reduction by the reagent CoCp 2 leads to the formation of a dipyrrin radical for both complexes [Cp 2 Co][UO 2 (OAc)( L • )] and [Cp 2 Co][UO 2 Cl( L • )].

The first catalyzed synthesis of Zn(i)–Zn(i) bonded compounds was realized through nickel-catalyzed dehydrocoupling of zinc(ii) hydrides.